Yamaha EF4500iSE Theory & Diagnostics Manual page 40

Yamaha Generator Theory & Diagnostics Guide
Then from either Green wire from the sub-coil to the
core. Any resistance reading from either test, indi-
cates that the stator is shorted to ground and must
be replaced.
Next test for them being shorted together. With the
meter on the highest resistance setting and one lead
on either the Brown or the Red wire from the main
coil and the other lead on either of the Green wires
from the sub-coil, check for an open circuit. Any
resistance reading indicates that the two coils are
shorted together and the stator must be replaced.
If the stator passes all of the above tests, it can be
eliminated from being the cause of the problem.
For the next test it will be necessary to remove the
front of the control panel and disconnect the con-
denser. To avoid electrical shock, do not touch the
terminals of the condenser. Short the terminals
together with an insulated screwdriver to discharge
it.
Using your analog meter on the RX1k ohm scale,
connect the meter leads to the condenser. The
meter should swing to one side and then quickly
return. If it does not, switch the meter leads on the
terminals.
If the meter still does not move or swings to one side
but does not return, then the condenser must be
replaced.
The rotor assembly will need to be removed in order
to perform the final two test. Refer to the Service
Manual for the model you are working on, for the
correct procedure.
SUB-COIL SHORT TO GROUND TEST
SUB-COIL TO MAIN COIL
SHORTED TOGETHER TEST
CONDENSER TEST
2-6